I want to dice them and put them on hot dogs and don't have a sandwich cooler prep table and was thinking warm raw diced tomatoes and onions might be tasty and keep everything HD happy...I didn't think I could keep them at room temperture.

PC, welcome to RF. I wouldn't hold the tomatoes and onions in any kind of heat. Have a small ice chest cooler with the containers sunk down into the ice. If you HD sees the containers sunk down into the ice and covered, he may like what he sees. If you have the tomatoes and onions at 140 degrees, the tomatoes will turn to mush and the onions will be slimy.....not something you would want.................take care.......pnwc

PC, welcome to RF. I wouldn't hold the tomatoes and onions in any kind of heat. Have a small ice chest cooler with the containers sunk down into the ice. If you HD sees the containers sunk down into the ice and covered, he may like what he sees. If you have the tomatoes and onions at 140 degrees, the tomatoes will turn to mush and the onions will be slimy.....not something you would want.................take care.......pnwc